Rocket oxidizer composition

ABSTRACT

A LIQUID ROCKET OXIDIZER WHOSE FREEZNG POINT IS BELOW -65*F. COMPRISING CIF3/ AND FROM 14 TO 40 WEIGHT PERCENT CIF5.

3,7il7,413 ROCKET UXlDlZER COMPOSITION Donald Pilipovich, Canoga Park,Calif, assignor to North American Rockwell Corporation No Drawing. FiledApr. 3, 1968, Ser. No. 718,989 Int. Cl. C0611 15/00 US. Cl. 149-109 2Claims ABSTRACT OF THE DISCLOSURE A liquid rocket oxidizer whosefreezing point is below a ..65 F. comprising ClE O and from 14 to 40weight percent C11 REFERENCES TO RELATED APPLICATIONS This invention isrelated to copending US. application Ser. No. 543,493 and to US. Pat.No. 3,354,656.

BACKGROUND OF THE INVENTION The field of interhalogen chemistry hasprovided several promising new oxidizers. One of the areas of highestutility of these new oxidizers is in the field of rocket missilepropulsion.

One of the newest of the interhalogen propellants is oxychlorinetrifluoride, ClF O. It has great utility as a liquid rocket oxidizer dueto its high specific impulse and density impulse. However, CIF O doeshave one disadvantage. Its freezing point is -37.2i0.5 C. For tacticalmissile applications, it has been stated that it is necessary for thepropellants to remain liquid at temperatures of at least -65 F. (54 C.).

The addition of conventional freezing point depressants to C1F O wouldhave the desired elfect of lowering the freezing point. However, theywould uniformly result in a deleterious effect to ClF Os highlyadvantageous specific impulse and density impulse values.

It would be desirable to provide a freezing point depressant for ClF Othat would not result in a reduction of more than about two percent ofClFgOs high density impulse.

It is an object of this invention to provide a means for depressing thefreezing point of oxychlorine trifiuoride, C1F O.

It is a further object of this invention to reduce the freezing point ofClF O to below 65 F.

It is a still further object of this invention to reduce the freezingpoint of ClF O to below 65 F. without reducing the density impulse ofthe resulting oxidizer to less than 98 percent of that of pure CIF O.

It is a still further object of this invention to reduce the freezingpoint of ClF O to below -6S F. without substantially changing itsproperties of specific impulse and density impulse.

Further objects and advantages of this invention will become apparentfrom the following description.

DESCRIPTION OF THE INVENTION It has been found that the addition of atleast 14 weight percent of ClF to ClF O results in the depression offreezing point of the mixture to below 65 F.

It has been further found that the addition of up to 40 weight percentof ClF results in a reduction in density impulse of C1F3O of typicallyless than two percent. Further, there is only a very minor effect onspecific impulse. This effect can be advantageous, that is, an increasein specific impulse can be observed.

It has been unexpectedly found that a mixture of ClF and ClF O accordingto the teachings of this invention results in a maximum specific impulsepoint for fuels containing carbon or boron. Examples of such fuels aremonomethylhydrazine and diborane. Further, this maximum 3,707,413Patented Dec. 26, 1972 ice boron atom in the fuel. If less oxygen thanthis is supplied,

either free carbon or CR is produced, depending on the oxidizer to fuelmixture ratio. If more oxygen than this is used, the compound carbondioxide is formed. As will be clear to those skilled in the art, thecompound CO is the most desirable reaction product, since it has thelowest molecular weight of all the possible carbon containing gaseousproducts.

Naturally the oxidizer combination of the instant invention is notlimited to use with fuels containing carbon or boron such as the twoexamples given above. The oxidizer combination is also suitable for usewith fuel such as hydrogen, hydrazine and metallized liquids. However,it is only with those fuels containing carbon or boron that a maximum inspecific impulse is noted at a stoichiometric ratio of oxygen in theoxidizer to carbon in the fuel of about 1:1.

The following examples illustrate the novel oxidizers of this case.

EXAMPLE I A mixture of 15 weight percent C11 in CIF O is made. Afreezing point determination showed a freezing point of -55 C. Thisoxidizer gave the specific impulse of 301 see. when tested with the fuelMHF-3 and a density impulse of 445.6 gram-sec./cc. Pure ClF O froze at38 C. and gave a specific impulse of 299 sec. and a density impulse of445 gram-sec./ cc.

EXAMPLE II 39 weight percent C11 in CIF O was found to have a freezingpoint of C. When tested with MMH it was found to have a specific impulseof 299.8 sec. and a density impulse of 439 gram-sec./cc. Pure ClF O withMMH had a specific impulse of 298.1 sec. and a density impulse of 443gram-sec./ cc.

It is to be understood that the above described embodiments are merelyillustrative of application of the principles of this invention. Thoseskilled in the art may readily devise other variations that will embodythe principles of the invention. It is, therefore, to be understood thatwithin the scope of the appended claims the invention may be practicedotherwise than as specifically described.

What is claimed is:

1. A rocket oxidizer composition consisting essentially of ClF O andfrom 14 to 40 weight percent GR.

2. The rocket oxidizer of claim 1 wherein the C11 comprises from 15 to25 weight percent of the mixture.

References Cited UNITED STATES PATENTS 3,170,282 2/1965 Kirshenbaum eta1. 1491 X 3,260,628 7/1966 Logan et a1. 1491 3,354,646 11/1967 Maya etal. 149-1 X 3,377,801 4/1968 Altman 149-1 X BENJAMIN R. PADGETT, PrimaryExaminer 10 S. I. LECHERT, JR., Assistant Examiner US. Cl. X.R. 149-1,22, 36

